Lesson The World’s Biomes 44 and Ecosystems What You Will Learn hat kinds of plants and animals live near your community? To describe a biome and an WHave you ever observed how they depend on each other? ecosystem Reading Strategy Draw a table like the one below. In the right column, write a result of the fact listed in the left column. Fact Result The sun provides energy. Secondary consumers are predators. This savannah in Kenya is an example of a grasslands biome. Decomposers break down What Is a Biome? dead plants and animals. A plant and animal community that covers a large geographical area is called a biome. A biome has certain kinds of plants and animals. It is located in a specific climate and generally has a spe- Terms to Know cific kind of soil. For example, a desert biome is located in a cli- biome, ecosystem, food chain mate that is very dry. Cacti and shrubs are among the plants that grow there. Lizards and snakes are some of the animals that live there. A desert biome anywhere in the world will have a similar climate, as well as similar plants and animals. Some of the major land biomes of the world include forest, grasslands, desert, and tundra. The ocean is another major biome. Look at Figure 3-4. It shows you the characteristics of some of the major world land biomes. What Is an Ecosystem? A biome can include several ecosystems. An ecosystem refers to all the living things and nonliving things within a certain area and the relationships among them. Living things include the plants, animals, and microbes (such as bacteria and fungi). The nonliving environment includes air, soil, water, and sunlight. An ecosystem contains everything that is needed for the plants and animals living there to survive. LESSON 4 The World’s Biomes and Ecosystems 109 Figure 3-4 World Land Biomes Biome Kinds of Plants Kinds of Animals Kind of Climate Tundra Lichens, mosses, and Polar bears, reindeer, caribou, Very cold, dry sometimes dwarf trees arctic foxes, hares, hawks, falcons Tropical rain forest Tall, closely spaced ever- Monkeys, apes, gorillas, leopards, Warm, often hot, and wet green trees, vines, flowers lizards, tree frogs, black panthers, colorful birds, snakes Temperate forest Broadleaf or needleleaf trees, Birds, raccoons, lynx, cougars, Temperatures and precipitation climbing vines, flowers bears, foxes, squirrels, deer, vary; warm to hot summers snakes, insects, spiders and cold winters Desert Cacti, low shrubs Lizards, snakes, jackrabbits, Very dry kangaroo rats, insects Grasslands Grasses, trees, flowers Antelope, bison, coyotes Mild, moderate temperatures and rainfall The relationship of living and nonliving things as water and minerals from the soil to grow. in an ecosystem can be seen in the food chain. Primary consumers include animals that eat Look at Figure 3-5. plants, such as rabbits and grasshoppers. Sec- The food chain shows how the living and non- ondary consumers are predators, or animals that living parts of an ecosystem are interrelated. The eat other animals. Finally, decomposers, such as sun provides the energy that the primary produc- bacteria, break down dead animals and plants into ers need to make food. Primary producers are nutrients that go back into the soil. The nutrients mainly green plants. Plants also need things such are used again by plants. Figure 3-5 The Food Chain NONLIVING SUBSTANCES Sunlight Minerals in soil PRIMARY PRODUCERS Green plants use energy from the sun to make food, and use minerals from the soil and water to grow. DECOMPOSERS Bacteria PRIMARY CONSUMERS Animals that eat plants, such as rabbits and grasshoppers SECONDARY CONSUMERS Animals that eat other animals 110 LESSON 4 The World’s Biomes and Ecosystems Using Your Skills Recalling Facts Answer the following questions about biomes and ecosystems. 1. What characteristics make up a biome? A biome has certain kinds of plants and animals, a specific climate, and a specific type of soil. 2. What are five major land biomes of the world? tundra, tropical rain forest, temperate forest, desert, grasslands 3. What things make up the living and nonliving parts of an ecosystem? living things include plants, animals, and microbes; nonliving things include the air, soil, water, and sunlight 4. What part of an ecosystem provides the energy needed for primary producers to make food? the sun 5. What role do decomposers play in the food chain? They break down dead animals and plants into nutrients. These nutrients are used by plants, and the process continues. Using Graphics Use Figures 3-4 and 3-5 to answer the questions. 1. What kinds of plants grow in the tundra? lichens, mosses, and sometimes dwarf trees 2. What kinds of animals could you expect to find in a grasslands biome? antelope, bison, and coyotes 3. What living things in the food chain are producers? green plants 4. What do producers use to make food? sunlight, and minerals and nutrients in the soil 5. What is the difference between primary and secondary consumers? Primary consumers are animals that eat plants; secondary consumers are animals that eat other animals. LESSON 4 The World’s Biomes and Ecosystems 111.